Can losartan (angiotensin II receptor antagonist) be taken concurrently with other medications?

From the Guidelines

Losartan should not be taken with ACE inhibitors or within 36 hours of the last dose of an ACE inhibitor, and it is recommended to substitute ACE inhibitors or ARBs with ARNI in patients with chronic symptomatic HFrEF NYHA class II or III to further reduce morbidity and mortality. When considering taking losartan with other medications, it is essential to exercise caution and consult a healthcare provider. The combination of losartan with other blood pressure-lowering medications, such as other ARBs, ACE inhibitors, or aliskiren, should be avoided to prevent excessive blood pressure reduction 1. Additionally, combining losartan with NSAIDs like ibuprofen may reduce its effectiveness and potentially harm kidney function. Potassium supplements or potassium-sparing diuretics should be used carefully with losartan, as they may cause dangerous potassium levels. Lithium levels may increase when taken with losartan, requiring close monitoring. The guidance provided by the 2017 ACC/AHA/HFSA focused update on the management of heart failure emphasizes the importance of careful consideration when combining losartan with other medications, particularly in patients with heart failure 1.

Some key points to consider when taking losartan with other medications include:

• Avoiding combinations that may lower blood pressure too much
• Using caution when combining losartan with NSAIDs or potassium supplements
• Monitoring lithium levels when taken with losartan
• Substituting ACE inhibitors or ARBs with ARNI in patients with chronic symptomatic HFrEF NYHA class II or III
• Consulting a healthcare provider before combining losartan with other medications.

It is also important to note that losartan can be taken with many other medications, but the specific combination and dosage should be determined by a healthcare provider, taking into account the individual patient's medical history and current health status 1.

From the FDA Drug Label

7.1 Agents Increasing Serum Potassium Coadministration of losartan with other drugs that raise serum potassium levels may result in hyperkalemia. Monitor serum potassium in such patients. 7.2 Lithium Increases in serum lithium concentrations and lithium toxicity have been reported during concomitant administration of lithium with angiotensin II receptor antagonists. Monitor serum lithium levels during concomitant use. 7.3 Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, coadministration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists (including losartan) may result in deterioration of renal function, including possible acute renal failure. 7.4 Dual Blockade of the Renin-Angiotensin System (RAS) Dual blockade of the RAS with angiotensin receptor blockers, ACE inhibitors, or aliskiren is associated with increased risks of hypotension, syncope, hyperkalemia, and changes in renal function (including acute renal failure) compared to monotherapy

Losartan can be taken with other medications, but with caution. The following medications require careful consideration:

• Agents that increase serum potassium: Monitor serum potassium levels to avoid hyperkalemia.
• Lithium: Monitor serum lithium levels to avoid lithium toxicity.
• NSAIDs: Monitor renal function periodically, especially in elderly or volume-depleted patients.
• Dual blockade of the RAS: Avoid combined use of RAS inhibitors, such as ACE inhibitors or aliskiren, due to increased risks of hypotension, syncope, hyperkalemia, and changes in renal function 2.

From the Research

Losartan Interactions with Other Medications

• Losartan potassium can be combined with hydrochlorothiazide to reduce blood pressure further than either drug given separately 3
• The use of losartan with potassium-sparing diuretics, such as spironolactone or triamterene, may cause hyperkalemia 4
• Losartan should not be administered to pregnant women and breast-feeding mothers, as it may disturb fetal growth or be harmful to the newborn 4
• Caution is advised when using losartan in patients with renal failure or liver dysfunction 4

Potential Interactions with Other Classes of Medications

• Diuretics, such as thiazide diuretics, may increase the risk of lithium toxicity when used concomitantly with lithium 5
• Nonsteroidal anti-inflammatory drugs (NSAIDs) may also be associated with lithium toxicity, although the relative interactive potential of specific NSAIDs is difficult to determine 5
• ACE inhibitors may impair lithium elimination, but further investigations are needed to identify patients at risk 5

Safety and Tolerability

• Losartan potassium is well tolerated, with dizziness being the only drug-related event reported more frequently with losartan potassium monotherapy than with placebo 3
• The adverse effect profile of the losartan potassium-hydrochlorothiazide combination resembles those for losartan potassium monotherapy and placebo 3